Recently, there was some media hype about the so-called negative effects of exercise and suggestions that it could actually be detrimental to health. Many couch potatoes jumped on the bandwagon, proclaiming they had been right all along  that their kind of sedentary lifestyle was preferable and healthier than an active one.

But what the article in question actually said was that a totally sedentary, overweight individual over the age of 50 should not suddenly embark on any intense aerobic activity like running and at the same time start severe dieting. The heart cannot cope with this sudden stress and starvation, increasing the likelihood of a heart attack. This does not mean they cannot do intense exercise; it means they should work up to it gradually under medical supervision.

Few people understand the importance of regular physical activity. They think their daily routine of shopping, housework and workplace activity is sufficient. As a result, 6 per cent of adults in India and 25 per cent of urban adults are clinically obese. The body mass index (BMI) or weight divided by height in metre squared is 30 or more, well above the acceptable norm of 23.

Statistics explain the reason for India being the diabetic capital of the world. Many are not yet diabetic but have Metabolic Syndrome X, which places them at high risk for heart attacks. Metabolic Syndrome X is diagnosed if you have:

All these parameters can return to normal with a dedicated approach to diet and exercise.

After an emotionally exhausting and stressful day at work, 30 minutes of brisk walking or a workout in the gym can reduce stress, elevate the mood and rejuvenate the body. This is because exercise releases chemicals from the calf muscles that increase the levels of mood elevating serotonin in the brain. Regular exercise combats depression and increases feelings of self worth.

With exercise the lipid profile becomes normal and this prevents any build-up of harmful plaques in the blood vessels. This, in turn, prevents strokes and heart attacks.

Many often complain they are too tired to exercise. But actually, regular physical activity boosts energy levels. A good nights sleep is the key to a productive day. Exercise does promote good sleep, but it needs to be completed at least an hour before bedtime. Or else the racy pumped-up feeling may not let you fall asleep. Students who want to study late can benefit from a short burst of high intensity exercise like a run around the house. It is healthier and probably more effective than coffee or other caffeine laced beverages.

Some of the chemicals released during exercise like the HSP (heat shock protein) help cells develop immunity and fight cancer and other diseases.

Exercise must be started young. The epidemic of childhood obesity is on the rise the world over. A child growing up in a family where no one exercises is unlikely to be motivated to do anything with spare time other than watch TV, play on the computer or eat snacks. Such children grow into obese adults with Syndrome X.

Walking for an hour and covering a distance of 4km in that time seven days a week is ideal. If you are between 20 and 50 years and have no health problems, jogging the same distance would be more beneficial. Children less than 10 years need to run for 20 minutes to half an hour every day. At least 20 minutes should be also spent on warming up, cooling down and stretching, preferably 10 minutes before and 10 minutes after exercise. Core strength is also essential for fitness and can be improved with sit-ups, push-ups and squats. Ten to 20 repetitions of each are all that are required.

Remember, exercise moderation is the key to success. Build up to your dream fitness level gradually to avoid strain to the heart, muscles, bones and joints.

Dr Gita Mathai is a paediatrician with a family practice at Vellore. Questions on health issues may be emailed to her at yourhealthgm@yahoo.co.in